While trying to configure pidgin to act as a console for TRM once known as Reuters’ Messenger, I came across this page at their sourceforge site which documents the magic runes, critically the User Name.

(Username is basically derived from the login name by replacing @ to dot and then adding @reuters.net)
Don’t forget that you may have unique password in Reuters network, not the same as your PC/Domain password.

…..there have been considerable changes to the SSL handling in the NSS module. One part of them seems to be that the default for SSL cipher suites now follows the recommendation to disable known unsecure suites, e.g. that use RC4.

You can change the settings with Tools -> Plugins -> NSS Preferences. On my company account, which is a OCS2007 installation, I needed to enable at least TLS_RSA_WITH_RC4_128_SHA or TLS_RSA_WITH_RC4_128_MD5 before SSL connections went through again.